Detection of small molecules using aptamers

authored by: Harshvardhan Modh
supervised by: Thomas Scheper
Abstract: Nucleic acid aptamers are versatile molecular recognition agents that bind to their targets with high affinity and selectivity. They can be selected by an in vitro procedure against a broad range of targets molecules including small molecules (molecular weight <1000 g/mol). Small molecules include toxins, antibiotics, molecular markers, drugs, and heavy metals ions. The detection of small molecules is important in different areas including public health, environmental monitoring, food safety, and antiterrorism. To meet the increasing demand for small molecule detection, methods are needed that are sensitive, reliable, rapid, cost effective and simple to use. In this context, aptamer-based detection platforms are becoming a promising alternative to conventional methods for small molecule detection. Concerning signal generation, mass-dependent detection methods, sandwich assay format and single-site binding assay formats are not always suitable for small molecule detection. The structural flexibility of aptamers enables the development of unique aptamer-based sensing platforms because aptamers fold into a well-defined three-dimensional structure upon binding to their target molecules. This specific property of aptamers allows to develop target-Induced dissociation (TID) of complementary oligonucleotide and target-induced structure switching (TISS)-based assays. In this PhD work, a novel aptamer-based assay (Apta-qPCR) was developed, which relies on TID for the detection of small molecules originating from biological, food and environmental samples. The Apta-qPCR assay was developed and optimized for the detection of ATP, ochratoxin A, and oxytetracycline. The assays are highly sensitive and selective for the target molecules. In addition, a rapid colorimetric assay was developed based on the TISS principle, which can detect ATP and ochratoxin A in 15 minutes.
Organisation(s): Institute of Technical Chemistry
Type: Doctoral thesis
No. of pages: 128
Publication date: 2019
Publication status: Published
Sustainable Development Goals: SDG 3 - Good Health and Well-being
Electronic version(s): https://doi.org/10.15488/4828 (Access: Open)